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Bittering Units : Real Extract (BU:RE) Calculator

2012 February 25
by Mad Alchemist

Some people have requested that I post a calculator for the BU:RE ratio. This uses degrees Plato instead of Specific Gravity. If you don’t work in degrees Plato and don’t know how to convert from Specific Gravity, here’s a quick formula you’ll need to know:

degrees Plato = Specific Gravity / 4

To briefly describe what BU:RE does you, it is roughly a 10 point scale that helps estimate beer balance (with 5 being balanced, 10 being very bitter, and 1 being very sweet). It takes into account the bitterness of a beer (in IBUs) as well as Real Extract (in degrees Plato, which is calculated for you via the Original Gravity and Final Gravity inputs). While it can’t account for X factors like roasted malts and water composition, it goes a long way toward quantifying balance and is my current favorite method for calculating it.

BU:RE = IBU / ((0.1808 * OG °P) + (0.8192 * FG °P))

BU:RE Calculator
Bitterness (IBU)
Original Gravity (°P)
Final Gravity (°P)
Bittering Units to Real Extract
BU:RE = IBU /((0.1808 * OG °P) + (0.8192 * FG °P))
by Ryan “Mad Alchemist” Shwayder

If you’d like to compare your beer against a style, here’s a large spreadsheet with all the BJCP style data you’ll need (including a column for the average BU:RE of the style). Beer Style Data (Google Docs)

Relative Bitterness Ratio (RBR)

2012 January 13

I have a new calculation that I’ve been using when determining the expected balance of my beer recipes. It is a child of the commonly-used Bitterness Ratio (BU:GU), and the numbers output can be read in the same way as BU:GU. However, the one thing that is taken into account with the Relative Bitterness Ratio (RBR) that BU:GU does not account for is Apparent Attenuation (ADF).

The higher the degree of Apparent Attenuation (ADF), the more fermentable sugars are consumed and the less residual sweetness is left behind. That means that as ADF gets higher, beer balance tends more toward the bitter end of the scale. As ADF gets lower, beer balance tends more toward the sweet end of the scale.

For example: A beer that starts out at an OG of 1.050 at 25 IBU would be said to have a Bitterness Ratio of 0.5. If it were split into two batches and one had an apparent attenuation of 80% (Beer A), while another had an apparent attenuation of 60% (Beer B), Beer A would be perceived to be more bitter than Beer B, as the latter has considerably more residual sweetness.

In the pages linked below, you can find out a plethora of information explaining details about the Relative Bitterness Ratio (RBR). If you aren’t interested in the details, I’ve included the formula for figuring out RBR as well as a simple calculator if you just want to input some numbers and get results.

To quickly explain the formula:

RBR = Relative Bitterness Ratio. ADF = Apparent Attenuation. 0.7655 is the average ADF of all beer styles. Since the Relative Bitterness Ratio takes into account balance relative to all beer styles, it uses this as a constant. You are comparing your beer’s ADF against the average ADF (0.7655), then adjusting the standard Bitterness Ratio accordingly (it goes up if your ADF is higher than average, down if your ADF is lower than average). Just like BU:GU, higher numbers mean more bitter, lower numbers mean less bitter, and 0.5 is roughly average balance.

RBR = (BU:GU) x (1 + (ADF - 0.7655))

Relative Bitterness Ratio Calculator
BU:GU Ratio
Apparent Attenuation (%)
Relative Bitterness Ratio
RBR = (BU:GU) x (1 + (ADF - 0.7655))
by Ryan “Mad Alchemist” Shwayder


UPDATE: The charts are broken. Google decided to update their API and make things not backward compatible. Unfortunately I don’t have time right now to dissect what the heck they did to make them work again.

The Perfectly Average Beer

2012 January 7
by Mad Alchemist

What’s the Perfectly Average Beer? Well, it’s all of the averages from the 2008 BJCP Style Guidelines in one beer. I was surprised after entering all of the data that the average beer is roughly what I would expect an average beer to look like. For example, the average bitterness ratio (BU:GU) is almost exactly 0.5, which I’ve always considered perfectly balanced for most malt bills.

Want the short version? The Perfectly Average Beer looks like this:

  • ABV: 5.8%
  • IBU: 28.6
  • SRM: 14
  • OG: 1.058
  • FG: 1.013
  • Bitterness Ratio: 0.5

Want some more details? I’m happy to oblige!

Alcohol By Volume ABV Low: 4.95% ABV High: 6.71% ABV Avg: 5.83%
Bitterness IBU Low: 20.68 IBU High: 36.51 IBU Avg: 28.60
Color SRM Low: 10.07 SRM High: 17.97 SRM Avg: 14.02
Original Gravity OG Low: 1.050 OG High: 1.065 OG Avg: 1.058
Final Gravity FG Low: 1.009 FG High: 1.016 FG Avg: 1.013
Attenuation Apparent Atten Avg: 76.55% Real Atten Avg: 62.71%
Bitterness Ratio IBU/OG Avg: 0.496

Want even MORE? Well, you’ll have to wait. I’m working up another post about beer balance and how attenuation figures into it, and I have a massive chart of all the style guidelines I’ll link at that time. Until then, enjoy knowing what the Perfectly Average Beer looks like.

Rhode Island Homebrew: Craft Brews Supplies

2012 January 7
tags: ,
by Mad Alchemist

I moved to Rhode Island last year and have been on the lookout for a great homebrew shop ever since. Massachusetts had a couple decent ones, but nothing compared to what I’m used to from Colorado.

I saw on RIFT (Rhode Island Fermentation Technicians homebrew club) that this opened up in Wyoming, RI, and decided to check it out. I’m pretty particular about my homebrew shops being an advanced all-grain armchair brew scientist.

What a pleasant surprise!

This is the cleanest homebrew shop I’ve ever been in. It’s neatly organized, and the location is great (just off 95 in a nice part of town, unlike many homebrew shops where you double-check that your doors are locked).

The folks who run the place are friendly and knowledgeable. You can even send them your recipe the day before you go and they’ll put all the grains together and crush them for yo. Or, you can go and grab exactly how much you need from bins rather than having to buy grain 1 lb at a time (or formulate a recipe on-the-spot with the staff).

The selection is quite good. They have most of the Weyermann malts along with several from Muntons and some special malts like Special B, Honey Malt, and Victory. Lots of adjuncts like candi sugar and vanilla beans alongside just about any of the additives you could need. I also found the Platinum Strain yeast from White Labs I was looking for, and they even carry some local hops, which is very cool.

This is the best homebrew shop in Rhode Island, bar none–I’ve been to all of them in my search, and this absolutely leaves the rest in the dust.

If you live in Rhode Island or eastern Connecticut, check out Craft Brews Supplies and you won’t be disappointed. This is now my official LHBS.


1133 Main st
Wyoming, RI 02898
ph: 401-539-BEER
alt: 401-539-2337
[email protected]

Beer and Brewing Charts

2011 December 29
by Mad Alchemist

Who doesn’t like charts? I decided to dig around for a while to see if anyone had made charts based on beer style guidelines and, if I couldn’t find anyway, I was going to make some myself. Well, someone else did it for me! Over at Lug Wrench Brewing, they created a series of charts about bitterness, alcohol, yeast, etc. A lot of useful stuff over there.

Perhaps my favorite one is the IBU to OG ratio chart, since I use the same information to balance my beers and this is a nice visual representation. Another chart I often look at is John Palmer’s age-old style spectrum, which compares malty vs. fruity and bitter vs. sweet in one chart. Another cool one is a motion chart of various BJCP guidelines made by the guy.

I might still make some sweet charts. If so, you’ll know.

Pintley: Beer Recommendation Site/App

2011 December 29
by Mad Alchemist

I recently found a website/smartphone app called Pintley. Essentially, you rate beers you’ve had and it gives you recommendations based on your taste. It’s a great idea and the site is very well-executed, so I’m very hopeful that it’ll catch on and I’ll start discovering new beers through the tool. Sign up for Pintley!

2011 Brewers Association Style Guidelines

2011 December 28
by Mad Alchemist

The 2011 Brewers Association Style Guidelines are available. I like to reference both the BA style guidelines and BJCP guidelines, then break the rules when I feel like it’s necessary to do so to hit the flavor I’m looking for.

Brew Masters

2011 January 21
by Mad Alchemist

A Discovery series I’ve fallen in love with: Brew Masters. From the Discovery website:

Sam Calagione, craft beer maestro and founder of Dogfish Head Brewery, and his partners in suds travel the world searching for exotic ingredients and discovering ancient techniques to produce beers of astounding originality.

While pompous beer geeks think he’s selling out (by the way, get over yourselves), this is a very interesting and entertaining series that will hopefully bring more attention the the craft, micro, and homebrewing scenes. I have my fingers crossed that the series will be successful and will continue to air.

Homebrew Stack Exchange

2011 January 21
by Mad Alchemist

A very nice website for getting homebrew questions answered quickly and knowledgeably is Homebrew Stack Exchange. You’ll frequently see some real names in the Homebrewing scene pop up there answering questions. Then there are random folk like me who know enough to pass along some advice and are willing to do so. Check out the site if you have any questions related to homebrewing you want answered.

Mashing the Perfect Sweet Stout

2010 April 15
tags: ,
by Mad Alchemist

Creating the perfect water profile and mash for a sweet stout is an exercise in contradiction. You want the beer to be very dark, sweet, malty, and full-bodied. It should have some roasted and toasty notes without astringency. To me, that translates to the following information concerning the mash and water profile: Keep the pH of the mash fairly high, around 5.6 (at room temperature). Keep the Chloride to Sulfate ratio high, around 3 to 1. Ensure Chloride and Sodium are both above 100, but below 150. Keep the temperature of the mash up around 158°F. It also means a thicker mash of around 1.25 quarts of water per pound of grain.

Where does the contradiction come in? Mostly with the grain bill. You’re looking at 10-15% of your grist being dark, roasted malt, which will drive the pH of the mash down significantly. It’s quite difficult to get a pH of more than 5.2-5.3 (at room temperature) without ending up with too much of something in the final beer (like sodium or bicarbonates). The reason I want to keep the pH up in the 5.4-5.6 range is because I use diastatically weak base malts for sweet stouts (like Munich or Maris Otter), and it’s better for enzymatic activity in that range. It’s also theoretically going to favor alpha amylase in this higher range, while beta amylase is favored a bit lower. Favoring alpha amylase is the same reason I keep the mash temperature up high at around 158°F.

The higher the Chloride to Sulfate ratio, the more malty the final beer is going to be. You need about 100ppm of Chloride before it has significant impact, and the same generally goes for Sodium (which rounds out the beer at that level, and I find that desirable in a sweet stout). You also, of course, need at least 50ppm of Calcium. The problem with the Calcium is that it lowers pH, but you really don’t want too much Bicarbonate in beer (some people believe it creates undesirable flavors, even though a lot of it will precipitate out, so I err on the side of caution here).

Okay, I think that’s enough of the reasoning behind the numbers I aim for with a sweet stout. On to the solution(s).

The first solution I came up with was to only worry about pH during the mash, and add all of the other minerals to the water after the mash. So, I’d add Sodium Bicarbonate and/or Calcium Carbonate during the mash to raise pH, then Calcium Chloride and Magnesium (or Calcium) Sulfate after the mash. Truthfully, this seemed to work out pretty well (and A.J. deLange corroborated), but I believe there is a better, and easier, way.

Don’t mash your roasted-and-kilned grains (e.g. chocolate and black malts). Roasted grains will drive the pH down considerably, so it’s difficult to keep the pH high no matter what fancy solution you use during the mash. Roasted grains have the wonderful benefit of not needing to be mashed. So, the best solution, in my opinion, is to mash everything except for your roasted grains in your MLT, and steep your roasted grains in a separate vessel (below 170 F) simultaneously at around 2 quarts per pound. Then, combine the wort created by the roasted grains with the mashed wort in the brew kettle.

If you don’t want to steep the grains, you can essentially brew a coffee with the dark grains with either a more traditional method (heat) or you can cold brew it overnight to really avoid the astringency as much as possible… it’ll just take longer. If you cold brew, you should probably bring the temperature of the concoction to 170 F after removing the grain to pasteurize it.

Then, you can add the coffee-like brew whenever you want (start of the boil, end of the boil, directly in the fermentation vessel, even just before bottling). All will impart different character, so experiment!

Note that you might not get full extraction from all roasted grains when steeping. According to some experiments run by John Palmer, it looks like Black Patent and Roasted Barley are some of the only roasted malts that have the same yield as mashing when steeped. As such, you might only exclude those from your sweet stout mash, or you can increase the amount of other grains accordingly (e.g. multiply the ounces of Chocolate Malt you use by ~1.5-1.6 to make up for the difference).

I would not recommend sparging with the roasted wort, in part because you’re going to impact the sparge pH pretty significantly, and in part because you’re going to leave some of your flavors behind.

Hitting the ideal concentrations of all ions in the brewing water as well as the ideal pH is very easy when you leave out your roasted malts (and any other malts that don’t need to be mashed, such as caramel/crystal). By steeping the roasted malts (and, optionally, your crystal malts) separate from the mash, you might end up with a much better sweet stout in the end. As someone commented, you could also steep the grains in a bag while you transfer to the boil kettle from your MLT, which sounds like a great idea.